This invention relates generally to generating profile curves and, more particularly, to systems and methods for generating two-dimensional profile curves of three-dimensional solid models.
Geometric models of components are often created with computer aided design (CAD) programs to enable a user to view a component in a variety of orientations. Often two-dimensional cross-sectional representations of such components are used by various CAD-dependent processes downstream from the CAD program including computer aided engineering (CAE) analysis, computer aided manufacturing (CAM) and drafting. Specifically, with respect to CAB analysis, two-dimensional CAE analysis often provides results comparable to full three-dimensional analysis, but requires less computational intensity and less time than three-dimensional analysis. Furthermore, with respect to CAM operations, tooling-paths are programmed in two-dimensional planes. Accordingly, two-dimensional tooling-paths include only a maximum revolved profile of the component in a two-dimensional plane which is simplified in comparison to a profile of the component in a three-dimensional definition.
Known profile curve generators use a plurality of intersecting planes to create two-dimensional representations of three-dimensional solids. The intersecting planes are extended through the three-dimensional solid at a plurality of angles disposed about an axis of rotation of the three-dimensional solid. Each intersection of the solid produces a set of curves at a given angle relative to the axis of rotation. The different sets of intersecting curves do not create a contiguous profile of the three-dimensional solid, but rather each set of curves is independently rotated into a two-dimensional plane of interest. To graphically reprint a full envelope of the three-dimensional solid, intersecting curves must be extended through the solid at selected angles or potential areas of the solid will not be graphically profiled. Such drafting programs require large amounts of disk storage space to store the numerous intersecting curves. Furthermore, such programs are time-consuming to execute because of the large amount of computations created as a result of the numerous intersections.
In an exemplary embodiment, a two-dimensional profile curve of a computer representation of a three-dimensional solid model is automatically generated. More specifically, and in one embodiment, a two-dimensional representation is created with a computer executing a profile curve generator without creating separate intersection lines that extend through the three-dimensional solid. The profile curve generator queries the three-dimensional solid to identify facts on the three-dimensional solid. The query of the three-dimensional solid begins after a revolved face is identified as a seed face. The query process continues until all the faces have been queried and processing returns to the seed face. As each revolved face is located, internal edge loops disposed within the face are ignored and a representative curve for the face is created in the two-dimensional plane.
The computer executing the algorithm is programmed to terminate the algorithm if a face edge is not identified which satisfies internal constraints programmed within the algorithm. The computer is also programmed to terminate the execution of the algorithm if the curve generated is not continuous. As a result, the algorithm enables the computer to generate contiguous curves and accurate two-dimensional representations of three-dimensional solids in a more cost-efficient and less time-consuming manner in comparison to known profile curve generators.